1. Technical Field
Apparatuses and methods consistent with exemplary embodiments relate to photo-sensing devices, and more particularly to an image sensor having light-leakage prevention structure to stabilize black levels.
2. Description of the Related Art
An image sensor converts photo charges corresponding to a captured image into electric signals, and is widely used in digital cameras, game devices, vision systems, and the like.
The image sensor may be a charge coupled device (CCD) and a complementary metal-oxide semiconductor (CMOS) device.
In general, the image sensor includes additional pixels for providing black levels or dark levels corresponding to reference levels irrelevant to the incident light. For example, the black level may depend on the operational temperature of the image sensor. Particularly when the incident light has high intensity, a portion of the incident light may arrive at the additional pixels through reflection, refraction and diffraction to affect the black levels. Also, photo carriers generated by the incident light may be diffused to the additional pixels to affect the black levels. Such phenomenon that is referred to as light-leakage phenomenon may distort the black levels and thus a quality of displayed images may be degraded.